Document Detail


Cathodic stripping voltammetric determination of doxazosin in urine and pharmaceutical tablets using carbon paste electrodes.
MedLine Citation:
PMID:  9338991     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Several voltammetric techniques were used to explore the reductive behaviour of the antihypertensive agent doxazosin on a bare carbon paste (CPE) and a Tenax-modified carbon paste electrode (TMCPE). The results indicate that the process is irreversible and fundamentally controlled by adsorption, which allows doxazosin to be accumulated at the electrode surface. The cathodic adsorptive stripping (AdS) response was evaluated with respect to pH, accumulation variables and instrumental parameters, using differential-pulse (DPV) and square-wave voltammetry (SWV) as redissolution techniques. In both cases, a voltammetric peak close to 0 V in Britton-Robinson buffer (pH 6.6) was obtained after a preconcentration step at 0.55 V for 3 min (2000 rpm) and a subsequent cathodic scan. When the TMCPE was used, the limits of detection were 4.35 x 10(-11) and 5.18 x 10(-11) M for AdS-DPV and AdS-SWV, respectively. The deposition time (3 min) was improved relative to that obtained by means of CPE (6 min). Under the optimum operational conditions, the doxazosin reduction peak showed a linear response in the range from 6 x 10(-11) to 1 x 10(-9) M by using AdS-DPV, with an RSD of 3.39% for 3 x 10(-8) M doxazosin solution (n = 10). A method was developed for the determination of doxazosin in human urine and formulations.
Authors:
A Arranz; S Fernández de Betoño; J M Moreda; A Cid; J F Arranz
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Analyst     Volume:  122     ISSN:  0003-2654     ISO Abbreviation:  Analyst     Publication Date:  1997 Aug 
Date Detail:
Created Date:  1997-11-18     Completed Date:  1997-11-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372652     Medline TA:  Analyst     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  849-54     Citation Subset:  IM    
Affiliation:
Departamento de Química Analítica, Facultad de Farmacia, Universidad del Pais Vasco EHU, Vitoria, Spain.
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MeSH Terms
Descriptor/Qualifier:
Adsorption
Antihypertensive Agents / urine*
Carbon
Doxazosin / urine*
Electrochemistry
Electrodes
Humans
Tablets / chemistry*
Chemical
Reg. No./Substance:
0/Antihypertensive Agents; 0/Tablets; 74191-85-8/Doxazosin; 7440-44-0/Carbon

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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